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.TH CURLOPT_RESOLVER_START_DATA 3 "14 Feb 2018" "libcurl 7.59.0" "curl_easy_setopt options"
.SH NAME
CURLOPT_RESOLVER_START_DATA \- custom pointer passed to the resolver start callback
.SH SYNOPSIS
#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_RESOLVER_START_DATA, void *pointer);
.SH DESCRIPTION
Pass a \fIpointer\fP that will be untouched by libcurl and passed as the third
argument in the resolver start callback set with
\fICURLOPT_RESOLVER_START_FUNCTION(3)\fP.
.SH DEFAULT
NULL
.SH PROTOCOLS
All
.SH EXAMPLE
.nf
static int resolver_start_cb(void *resolver_state, void *reserved,
                             void *userdata)
{
  (void)reserved;
  printf("Received resolver_state=%p userdata=%p\\n",
         resolver_state, userdata);
  return 0;
}

CURL *curl = curl_easy_init();
if(curl) {
  curl_easy_setopt(curl, CURLOPT_RESOLVER_START_FUNCTION, resolver_start_cb);
  curl_easy_setopt(curl, CURLOPT_RESOLVER_START_DATA, curl);
  curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
  curl_easy_perform(curl);
  curl_easy_cleanup(curl);
}
.fi
.SH AVAILABILITY
Added in 7.59.0
.SH RETURN VALUE
Returns CURLE_OK
.SH "SEE ALSO"
.BR CURLOPT_RESOLVER_START_FUNCTION "(3) "
